Which mold design would be more professional/practical for a plaster bust casting?
Hi everyone,
I am currently designing a mold for a plaster bust and I am unsure which gating/venting setup would be the more professional or practical solution for plaster casting. The mold itself would consist of a silicone inner mold (two parts) supported by a rigid 3D-printed outer shell (mother mold).
I attached two alternatives.
Alternative 1
The entire mold is rotated about 60°.
This orientation avoids undercuts in the face area (nose, chin etc.), so the air can rise naturally and escape more easily.
In this setup:
- plaster and trapped air use the same channel
- the single opening acts as both:
- pouring channel (sprue)
- air vent
Alternative 2
In this version the mold remains horizontal and uses:
- one dedicated pouring channel (sprue)
- one separate air vent at the highest point of the mold in side view
The plaster is poured through the main sprue, while the displaced air exits through the vent channel.
However, this version would require additional cleanup afterwards because both the sprue and vent would need to be removed and refinished.
My question is:
Which option would be considered the more “professional” and practical approach for plaster casting?
Would you prioritize:
- the rotated setup with minimal cleanup (Alternative 1), or
- the sprue + vent system (Alternative 2), even if it requires more post-processing?